Sack production



w. NIEME YER SACK PRODUCTION June 29, 1965 4 Sheets-Sheet 1 Filed Aug. 6, 1962 June 29, 1965 Filed Aug. 6, 1962 W. NIEMEYER SACK PRODUCTION 4 Sheets-Sheet 2 June 29, 1965 w. NIEMEYER SACK PRODUCTION Filed Aug. 6, 1962 4 Sheets-She et 3 lnventor: MIYILLY NIEMEYER n a m. Ins Affornef WL NIEMEYER SACK PRODUCTION June 29, 1965 4 Sheets-Sheet 4 Filed Aug. 6, 1962 lnvenzor: WILLY ZJIEMEYER .Y

, Fig. 14

United States Patent 3,191,850 SACK PRODUCTIGN Willy Niemeyer, Natrup Hagen, Germany, assignor to Windmfiller & Holscher, Lengerich, Germany, a firm of Germany Filed Aug. 6, 1962, Ser. No. 214,902 Claims. (Cl. 229-625) In some known sacks of paper or the like use is made of a filling valve with a fold in the outside end of the valve. These sacks are of the block-bottom type. However, a difficulty with this type of sack is that the paper of which the valve is made is so stiff that the inner edge of it which forms lips does not reliably close the sack.

We have now devised a new type of sack titted with a valve which consists of a sheet of paper and a sheet of synthetic resin, the inside margin of the synthetic resin projecting inwards beyond the inside margin of the paper so as to form flexible lips which give a reliable sealing of the sack. The paper and the synthetic resin sheets of which the valve is composed are displaced in relation to each. other and the synthetic resin sheet and is folded round the fold in the outside end of the paper. p

In a preferred method of making the new valve the synthetic resin and the paper for making the sheets in the valve is drawn from two rollers and are superimposed. These two webs are then partially severed transversely and the sites at which severing has taken place are offset in the direction of travel. Finally the superimposed webs are torn off in pairs of sheets.

Preferably the sack fitted with the valve is of the multiwall type, that is to say, it has .at least two layers to its walls.

The novel valve and the method of making it are now described with reference to the accompanying drawings.

FIGURE 1 shows the two superimposed webs of material, the plastic web being drawn backwards.

FIGURE 2 shows the separation of a sheet of paper and a sheet of synthetic resin which are offset in relation to each other.

FIGURE 3 shows the two sheets for making a valve after folding and removal out of the line of the webs.

. FIGURE 4 is a side view of what is shown in FIG- URE 3.

FIGURE 5 shows the two sheets for making a valve, one of the sheets in front of the fold having been glued to the open block-bottom of a block-bottom sack in process of manufacture.

FIGURE 6 shows a block-bottom in accordance with FIGURE 5 after the folding down of one of the side leaves of the block-bottom.

FIGURE 7 is a block-bottom according to FIGURES 5 and 6 after the folding down of the other leaf.

FIG. 8 illustrates in perspective the plastic sheet and paper sheet before being folded together;

FIG. 9 illustrates the valve insert in perspective consisting of the plastic and paper sheets after the initial folding step;

FIG. 10 illustrates in perspective the plan view of FIG. 5 wherein the valve insert of FIG. 9 has been glued to the open block-bottom of a block-bottom sack;

FIG. 11 illustrates in perspective the bag of FIG. 10 after the end flaps had been folded over and glued together and the bag had been filled thereby causing the valve insert to form a valve passage;

FIG. 12 is a cross-sectional view in perspective along line XIIXII of FIG. 11 in which, for the sake of clarity, the sack is illustrated as consisting only of one layer of material;

3,191,850 Patented June Zii, 1965 FIG. 13 illustrates in perspective the finished valve of FIG. 11; and

FIG. 14 is a cross-sectional view in perspective along line XIVXIV of FIG. 13.

In FIGURE 1, 1 denotes a lower web of paper and 2 denotes a web of synthetic resin lying on it. The direction and movement of the two webs is denoted by the arrow 3. The webs are laterally ofiset. At the site 4- both webs are partially severed. The short lines indicate the out. Between these short lines the material is left uncut. This partial severing permits a subsequent complete separation by tearing.

While the paper web 1 is moved along in the plane of the drawing, the upper web 2 of synthetic resin is diverted upwards so that the transverse sites of severing l and 4" are offset. The site 4' is set in front of the site 4" by a distance b. The upward movement of the upper web cannot be seen from FIGURE 4 as it is a plan. When the two webs are placed together again the sites of severing 4 are now a distance b from the sites 4 of partial severing. The distance b corresponds to the desired degree of offset of the synthetic resin web in relation to the paper web. Now both the webs are fed forwards so that the distance b between the sites of 4 and 4" of partial severing remain constant.

In FIGURE 2, 5 denotes a rectangular region in which the two superimposed webs are held stationary for a short time. At the dot-dash line 6 the front end of the Web is folded behind the front edge 7 of the synthetic resin web. Here the two webs are tugged forwards with increased speed and are torn off or detached along sites 4' and 4 at 8 and 9.

Owing to the increased speed with which they are fed forward the two sheets for forming a valve, as shown in FIGURE 3, are pulled away from the web. The two sheets, together denoted by the general reference number 10, that is to say the paper sheet 11 and the synthetic resin sheet 12 lying on top of it, are offset by a lateral distance a and by a distance b in the axial direction that is to say the direction of movement. The fold 6 is made in both sheets a short distance behind the front edge 7 of the synthetic resin sheet 12. Then the part c in front of the fold is bent back in relation to the rest of the sheet in a direction opposite to the direction of movement. This is not shown in the drawing. Next adhesive is applied to the exposed leaves which go to form the block-bottom of the sack (FIGURE 5) and to the synthetic resin sheet 12. Since the layer of adhesive applied is not visible it is indicated by broken hatching in FIG- URE 5. In this figure it will be seen that the two sheets which are to form the valve have been turned over and are laid in the bottom of the eventual block-bottom sack 13 which is in the course of production, in such a manner that the fold 6 is pointing forward While the folded over piece 6 is glued in position. The direction of movement of the blockbottom sack is denoted by the arrow 14. The largely invisible line 15 denotes the end of the corner leaf or flap 16 which lies short of the paper sheet 11, for example, small distance d, and short of the synthetic resin sheet a distance d+b. Therefore the synthetic resin sheet projects into the inside of the sack. It should be noted that not only is the paper sheet bonded to the corner flap 16 in the region of the bent over portion, but also the synthetic resin sheet 12 is glued in position, so that the two sheets, which are not glued together, are held firmly fixed .to the corner flap. It therefore follows that the synthetic resin sheet cannot be pushed out of position when the filling nozzle is inserted.

The valve 10 is inserted into the block-bottom from one side so that after the lateral leaves or flaps of the block-bottom are folded over a closed tube results in which parts of the lateral flaps are not pushed into it.

The adhesive applied, which is shown in FIGURE 6, is visible and therefore is shown in ordinary cross-hatching as opposed to broken cross-hatching of FIG. 5. This adhesive is applied to the lateral flap or leaves 17 which partially forms the block-bottom and which surrounds the part 18 of the valve 18. Adhesive is also applied to this part 18. The other lateral flap 19 of the block-bottom to which part of the valve 10 has already been glued is illustrated in the already folded over position in FIG. 6.

FIGURE 7 shows a block bottom after the folding over and bonding of a lateral flap 17 of the block bottom, and also of the part 13 of the valve. There results two longitudinal seams 20 and 21, that is to say two seams parallel to the axis of the valve, in the tube-like valve. The lateral fiap 19 of the bottom does not extend into this seam. The two longitudinal margins of the paper sheet of the valve are stuck together in the seam 20 while the two longitudinal margins of the synthetic resin sheet form the seam 21.

The outer ends of the valve 10 are in line with the bottom corners 22 and 23 of the sack. The front edge is suificiently reinforced by the fold 6, so as to provide a stronger front edge zone.

It is of course to be understood that what has been described above is applicable not only to paper sack production but also to the production of sacks of paperlike materials. It is, therefore, not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

What I claim is:

1. In a paper or the like bag of the valve type having overlapping end flaps, a filling valve arranged underneath said overlying end flaps, said valve comprising a first sheet of paper which is inserted between said overlapping end flaps, said first sheet including a folded over exterior front edge portion, a second sheet of synthetic resin which is inserted betwen said overlapping end flaps and is arranged adjacent to said first sheet, a first portion of said second sheet extending underneath said folded over front edge portion of said first sheet and a second portion of said second sheet extending interiorly of said bag substantially beyond the innermost edge with respect to said bag of said first sheet, thereby forming sealing means inside said bag.

2. In a self-sealing valve bag of the type having overlapping end fiaps within which the valve is inserted and which form an opening through which material is delivered to the interior of the bag, said self-sealing filling valve, comprising in combination, a first sheet of relatively stiff paper, said first sheet including a front edge portion folded back upon itself along a line substantially parallel to the adjacent side edge of said bag, and further including a first rear portion which is oriented and extends towards the interior of said bag, a second sheet of relatively thin flexible synthetic resin at least partially underlapping said first sheet, said second sheet including a front edge portion arranged underneath said front edge portion of said first sheet and being folded back upon itself along a line substantially parallel to and substantially contiguous with said line of said folded front edge portion of said first sheet, and further including a second rear portion which is oriented and extends towards the interior of said bag substantially beyond the interior end of said first rear portion, whereby said folded front edge portion of said first sheet defines at least partially the inside walls of said filling valve and said rear portion of said second sheet forms self-sealing wall means for said filling valve.

3. In a paper or the like bag, the filling valve as set forth in claim 2, wherein said first sheet of paper and second sheet of synthetic resin are offset with respect to each other in a direction perpendicular to the longitudinal axis of the bottom of the bag, said first and second sheets forming longitudinal seams with their respective folded over sides which are parallel to said longitudinal axis of said bottom of the bag.

4. In a paper or the like bag, the filling valve as set forth in claim 2, wherein said first and second sheets are of equal length and are offset in the longitudinal axial direction of the bottom of the bag.

5. In a self-sealing valve bag of the type having overlapping end flaps forming an opening through which material is delivered to the interior of the bag, a self-sealing filling valve arranged underneath a pair of said overlapping end flaps and operatively glued to said pair of overlapping end flaps and to the adjacent bottom walls of said bag, said filling valve comprising, a first sheet of relatively stiff paper, said first sheet of paper including a front edge portion folded back upon itself along a line substantially parallel to the adjacent side edge of said bag, and further including a first rear portion which is oriented and extends interiorly of said bag, a second sheet of relatively thin flexible synthetic resin underlapping said first sheet, said second sheet including a front edge portion arranged underneath said front edge portion of said first sheet and being also folded back upon itself along a line substantially parallel to and substantially contiguous with said line of said front edge portion of said first sheet, and further including a second rear portion which extends interiorly of said bag substantially beyond the innermost portion of said first rear portion, whereby said folded front edge portion of said first sheet defines the inside walls of said filling valve and said rear portion of said second sheet forms self-sealing wall means for said filling valve.

References Cited by the Examiner UNITED STATES PATENTS 231,642 8/80 Appel 93-14 1,926,421 9/33 Andreas 93-14 1,951,471 3/34 Coty 93-14 3,000,551 9/61 Atwood 229-625 3,065,899 11/62 Means et al. 229-625 FOREIGN PATENTS 140,941 4/51 Australia.

173,000 11/52 Austria.

882,237 2/43 France.

963,832 5/57 Germany.

968,374 2/ 5 8 Germany.

929,954 6/63 Great Britain.

FRANKLIN T. GARRETT, Primary Examiner.

EARLE J. DRUMMOND, Examiner. 

1. IN A PAPER OR THE LIKE BAG OF THE VALVE HAVING OVERLAPPING END FLAPS, A FILLING VALVE ARRANGED UNDERNEATH SAID OVERLYING END FLAPS, SAID VALVE COMPRISING A FIRST SHEET OF PAPER WHICH IS INSERTED BETWEEN SAID OVERLAPPING END FLAPS, SAID FIRST SHEET INCLUDING A FOLDED OVER EXTERIOR FRONT EDGE PORTION, A SECOND SHEET OF SYNTHETIC RESIN WHICH IS INSERTED BETWEEN SAID FIRST SHEET, A FIRST FLAPS AND IS ARRANGED ADJACENT TO SAID FIRST SHEET, A FIRST PORTION OF SAID SECOND SHEET EXTENDING UNDERNEATH SAID FOLDED OVER FRONT EDGE PORTION OF SAID FIRST SHEET AND A SECOND PORTION OF SAID SECOND SHEET EXTENDING INTERIORLY OF SAID BAG SUBSTANTIALLY BEYOND THE INNERMOST EDGE WITH RESPECT TO SAID BAG OF SAID FIRST SHEET, THEREBY FORMING SEALING MEANS INSIDE SAID BAG. 